You need to save the object of the restore session the moment you start the session. If you have saved it to a variable, you can use it with the FileRestore parameter.

Submit the path to any of disks that were mounted during the restore.

You need to know a temporary path to at least one of the VM virtual disks that were mounted during the restore session. Note that when you provide path to one virtual disk, as the result of the cmdlet all disk of the VM will be unmounted.